Shard of Faintstone
Shards of Faintstone are Upgrade Materials in Demon's Souls.

In-Game Description

Cold, holy ore that shines dimly. Enhances straight swords, axes, hammers, and so on.
The faintstone's power will also cause the user of a weapon blessed with it to slowly regenerate HP. Weapons can be strengthened by Faintstone up to a maximum of level 5.

Drop from Shaman Depraved Ones in 5-2

Filthy Woman - Purchase 10,000 souls